1. Field of the Invention
The present invention relates to a display device and driving module thereof, and more particularly, to a display device reducing power consumption and increasing brightness via changing sub-pixel arrangement method and driving module thereof.
2. Description of the Prior Art
A liquid crystal display (LCD) is a flat panel display which has the advantages of low radiation, light weight and low power consumption and is widely used in various information technology (IT) products, such as notebook computers, personal digital assistants (PDA), and mobile phones. An active matrix thin film transistor (TFT) LCD is the most commonly used transistor type in LCD families, and particularly in the large-size LCD family. A driving system installed in the LCD includes a timing controller, source drivers and gate drivers. The source and gate drivers respectively control data lines and scan lines, which intersect to form a cell matrix. Each intersection is a cell including crystal display molecules and a TFT. In the driving system, the gate drivers are responsible for transmitting scan signals to gates of the TFTs to turn on the TFTs on the panel. The source drivers are responsible for converting digital image data, sent by the timing controller, into analog voltage signals and outputting the voltage signals to sources of the TFTs. When a TFT receives the voltage signals, a corresponding liquid crystal molecule has a terminal whose voltage changes to equalize the drain voltage of the TFT, which thereby changes its own twist angle. The rate that light penetrates the liquid crystal molecule is changed accordingly, allowing different colors to be displayed on the panel.
An image quality of the LCD can be determined via counting a number of pixels of the LCD located in a direction. For example, the user may acquire a reference of determining the image quality of the LCD via calculating the pixels per inch (PPI). Please refer to FIG. 1, which is a schematic diagram of the relationship between the image quality and the PPI. As shown in FIG. 1, the image quality is proportional to the PPI. However, recognizing ability of the eyes has a limit. When the PPI of the LCD exceeds a threshold, the eyes generally cannot recognize each pixel of the LCD. In other words, the image viewed by the eyes would become no-grid if the PPI of the LCD exceeds the threshold.
For example, under a condition that the visual acuity of the user is 1.0 and a distance between the eyes and the LCD is 12 inches, it may be difficult for the user to recognize distances between the pixels of the LCD when the PPI of the LCD exceeds 286. In other words, the image received by the eyes becomes no-grid if the PPI of the LCD reaches 286. In such a condition, the number of sub-pixels corresponding to each pixel can be accordingly decreased, to increase the aperture ratio and to reduce the power consumption of the LCD. Thus, how to decrease the number of sub-pixel while maintaining the image quality becomes a topic to be discussed.